If you have an average cost of acquisition through other paid media channels then that may be a good starting point. One good exercise is to try and determine

If you have an average cost of acquisition through other paid media channels then that may be a good starting point. One good exercise is to try and determine the current value of the partner's inventory (emails, placement in publications, etc) that will be used to promote the co-brand. Your goal should be to structure the deal in such a way that you can meet or exceed the current value of that inventory for the partner and still be economically viable for you. Also, you may want to think about developing a tiered structure that gives monetary incentive to the partner if they deliver higher volumes of leads/sales. Hope this is helpful.